Property, Plant, and Equipment Property, Plant and Equipment (Secured Financing Agreements) (Details) - Equipment Financings - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Property, plant and equipment gross [Member]
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	$ 83,718	$ 71,403
Property, plant and equipment gross [Member] | Machinery and equipment
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	68,578	63,305
Property, plant and equipment gross [Member] | Construction in process
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	15,140	8,098
Property, plant and equipment net [Member]
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	70,163	60,718
Property, plant and equipment net [Member] | Machinery and equipment
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	55,023	52,620
Property, plant and equipment net [Member] | Construction in process
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	$ 15,140	$ 8,098